JPS622875B2 - - Google Patents
Info
- Publication number
- JPS622875B2 JPS622875B2 JP1147678A JP1147678A JPS622875B2 JP S622875 B2 JPS622875 B2 JP S622875B2 JP 1147678 A JP1147678 A JP 1147678A JP 1147678 A JP1147678 A JP 1147678A JP S622875 B2 JPS622875 B2 JP S622875B2
- Authority
- JP
- Japan
- Prior art keywords
- wastewater
- zeolite
- cation exchanger
- regeneration
- amount
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 45
- 239000002351 wastewater Substances 0.000 claims description 40
- 150000001768 cations Chemical class 0.000 claims description 34
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical group O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 claims description 31
- 229910021536 Zeolite Inorganic materials 0.000 claims description 30
- 239000010457 zeolite Substances 0.000 claims description 30
- 238000000034 method Methods 0.000 claims description 28
- 239000007788 liquid Substances 0.000 claims description 27
- 230000001172 regenerating effect Effects 0.000 claims description 19
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 16
- 239000003729 cation exchange resin Substances 0.000 claims description 12
- 239000007789 gas Substances 0.000 claims description 10
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 claims description 9
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 claims description 8
- 239000011780 sodium chloride Substances 0.000 claims description 8
- 229910001415 sodium ion Inorganic materials 0.000 claims description 5
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical compound [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 claims description 4
- 239000007864 aqueous solution Substances 0.000 claims description 3
- 150000002500 ions Chemical class 0.000 claims description 2
- 238000005341 cation exchange Methods 0.000 claims 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L sodium carbonate Substances [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims 2
- 229910000029 sodium carbonate Inorganic materials 0.000 claims 1
- 239000000243 solution Substances 0.000 description 28
- 239000011734 sodium Substances 0.000 description 26
- 238000011069 regeneration method Methods 0.000 description 25
- 230000008929 regeneration Effects 0.000 description 22
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 16
- 238000005342 ion exchange Methods 0.000 description 14
- 239000012492 regenerant Substances 0.000 description 13
- 238000001179 sorption measurement Methods 0.000 description 13
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 12
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- 239000002699 waste material Substances 0.000 description 5
- 229940023913 cation exchange resins Drugs 0.000 description 4
- 239000011347 resin Substances 0.000 description 4
- 229920005989 resin Polymers 0.000 description 4
- 238000005406 washing Methods 0.000 description 4
- 239000002253 acid Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 239000011259 mixed solution Substances 0.000 description 3
- 238000004065 wastewater treatment Methods 0.000 description 3
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 239000004793 Polystyrene Substances 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- 238000003795 desorption Methods 0.000 description 2
- 238000002309 gasification Methods 0.000 description 2
- 229920002223 polystyrene Polymers 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 241000251468 Actinopterygii Species 0.000 description 1
- 241000195493 Cryptophyta Species 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910000272 alkali metal oxide Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910001860 alkaline earth metal hydroxide Inorganic materials 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000003841 chloride salts Chemical class 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000010494 dissociation reaction Methods 0.000 description 1
- 230000005593 dissociations Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000012851 eutrophication Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000010842 industrial wastewater Substances 0.000 description 1
- 239000003456 ion exchange resin Substances 0.000 description 1
- 229920003303 ion-exchange polymer Polymers 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 1
- 235000019645 odor Nutrition 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
Landscapes
- Treatment Of Water By Ion Exchange (AREA)
Description
本発明は排水中のアンモニア性窒素除去法に関
し、特に排水中のアンモニア性窒素をイオン交換
吸着した陽イオン交換体層を効率的に再生して再
使用する排水中のアンモニア性窒素除去法に関す
る。
産業排水又は家庭下水の処理法の主流である活
性汚泥法及び活性炭吸着法では、排水中の有機物
を除去して清澄な水にすることはできるが、排水
中のアンモニア性窒素(以下NH4−Nと略称す
る)は除去できずそのまま放出される。ところ
が、このNH4−Nは藻類に対して窒素の補給源と
なるため、排水の富栄養化が促進され生物の成長
のバランスをくずし、いわゆる赤潮発生の原因と
なり、魚類の大量死滅を招いたり、又、湖沼では
悪臭の発生源となる。このため、排水中のNH4−
Nは公害問題として社会の注目を浴び、NH4−N
の放出は法規制の方向にあり、早急なNH4−N除
去技術の確立が強く望まれている。
排水中のNH4−Nの除去には、アンモニアスト
リツピング、生物処理、化学的処理及びイオン交
換吸着法等各種の方法が試みられているが、これ
ら各法にはそれぞれ一長一短があり未だ決め手と
なる方法は開発されていない。
ゼオライト又は陽イオン交換樹脂等の陽イオン
交換体をNH4−Nを含む排水と接触させ、排水中
のNH4−Nをイオン交換吸着除去する方法は簡単
で優れた方法である。排水中のNH4−N除去に陽
イオン交換体を使用する場合、吸着操作及びNH4
−Nをイオン交換吸着した陽イオン交換体の再生
操作を繰返し行なうサイクル方式を採用するのが
経済的見地から望ましい。したがつて、従来より
工業的に実施されているイオン交換樹脂を使用す
る純水製造装置あるいは硬水軟化装置等における
ものと同様な充填塔に陽イオン交換体を充填し、
これに排水を通水し、下記(1)式に示されるように
NH4−Nをイオン交換吸着した後、アルカリ金属
又はアルカリ土類金属の水酸化物、炭酸塩及び塩
化物等の水溶液を通液し、下記(2)式に示されるよ
うにNH4−Nを脱離する方法により、陽イオン交
換体のNH4−Nイオン交換吸着能を回復させる再
生方法がとられている。
R・Na+NH4 +→R・NH4+Na+ (1)
R・NH4+Na+→R・Na+NH4 + (2)
しかし、このような再生法においては、陽イオ
ン交換体の吸着に対する選択性がNH4 +≧Na+で
あるため、NH4 +をイオン交換吸着した陽イオン
交換体の再生には大量のNa+を必要とし、かつ再
生に長時間を要す。更に、脱離したNH4 +を含む
再生廃液の排出は避けられない。又、再生後の陽
イオン交換体充填層には、脱離したNH4 +が若干
残留するため、充填層内を水洗する必要がある。
本発明はこのような現状に鑑みてなされたもの
であり、その目的は、NH4−Nをイオン交換吸着
した陽イオン交換体とNa+等の接触を効果的に行
なわせると同時に脱離したNH4−Nをガス化する
ことにより、効率的に陽イオン交換体の再生を行
なう排水中のNH4−N除去法を提供することであ
る。
本発明は上記目的を達成するため次の構成をと
るものである。すなわち、本発明の排水中のアン
モニア性窒素除去法は、アンモニア性窒素をイオ
ン交換吸着した陽イオン交換体層にPH10以上のナ
トリウムイオン(Na+)含有再生液を供給すると
共にガスを導通してイオン交換体層を再生するこ
とを特徴とするものである。
本発明者等は、NH4−Nをイオン交換吸着した
陽イオン交換体をNa+を含む再生液で再生する場
合、陽イオン交換体から脱離したNH4−Nが再生
液中に存在するとそれが陽イオン交換体の再生に
悪影響を与えることを実験により確認し、この脱
離NH4−Nが再生液中に存在しないようにする手
段につき検討を重ねた結果本発明を完成したもの
である。
本発明によれば、このように陽イオン交換体か
ら脱離したNH4−Nが再生液中に存在しないよう
にするため、再生液としてPH10以上の強アルカリ
性のNa+含有再生液を使用することにより系内の
NH4 +をNH3に転換し、かつ再生時にガス例えば
空気を陽イオン交換体層内に導通し(吹き込ん
で)それにより脱離したNH4−NすなわちNH3を
系外に放散して(以下これをガス化と略記する)
再生液中に残留しないようにすることができる。
この際の再生液のPHは10以上とするのが好果的で
あり、これより低いとガス化率が著しく低下す
る。このことは、水溶液中におけるNH3及び
NH4 +の存在比について次のような解離定数の検
討によつて確認できる。
水溶液中におけるNH3及びNH4 +は次式に示さ
れる状態で存在する。
NH3+H2ONH4 ++OH- (3)
この場合のNH3の存在百分率は、次のようにし
て算出することができる。
K=〔NH4 +〕〔OH−〕/〔NH3〕〔
H2O〕
希薄溶液では、〔H2O〕=一定であり、したがつ
て、
Kb=〔NH+〕〔OH〕/〔NH3〕
又、Kw=〔H+〕〔OH-〕より
〔OH-〕=Kw/〔H+〕
よつて、
ここで、250℃におけるKbは1.8×10-5mol/
、Kwは10-14(mol/)2として、各PHにお
けるNH3の百分率が算出できる。例えば、25℃、
PH10においては、
となり、このようにしてPH7〜11におけるNH3百
分率は下表のとおりとなる。
The present invention relates to a method for removing ammoniacal nitrogen from wastewater, and more particularly to a method for removing ammoniacal nitrogen from wastewater by efficiently regenerating and reusing a cation exchanger layer that has ion-exchanged and adsorbed ammoniacal nitrogen from wastewater. The activated sludge method and activated carbon adsorption method, which are the mainstream treatment methods for industrial wastewater or domestic sewage, can remove organic matter from wastewater and make it clear water, but ammonia nitrogen (hereinafter referred to as NH 4 − (abbreviated as N) cannot be removed and is released as is. However, since this NH 4 -N acts as a nitrogen supply source for algae, it promotes eutrophication of wastewater and disrupts the balance of biological growth, causing so-called red tide, which can lead to mass die-off of fish. In addition, it is a source of bad odors in lakes and marshes. Therefore, NH 4 − in wastewater
N has attracted social attention as a pollution problem, and NH 4 −N
The release of NH 4 -N is subject to legal regulation, and there is a strong desire to establish a technology for removing NH 4 -N as soon as possible. Various methods have been attempted to remove NH 4 -N from wastewater, including ammonia stripping, biological treatment, chemical treatment, and ion exchange adsorption, but each of these methods has its own advantages and disadvantages, and no definitive solution has yet been reached. No method has been developed to do so. A simple and excellent method is to bring a cation exchanger such as zeolite or a cation exchange resin into contact with wastewater containing NH4 - N, and remove NH4 -N in the wastewater by ion exchange adsorption. When using a cation exchanger to remove NH 4 -N from wastewater, adsorption operation and NH 4
From an economic standpoint, it is desirable to adopt a cycle system in which a cation exchanger on which -N is ion-exchanged and adsorbed is repeatedly regenerated. Therefore, a cation exchanger is packed in a packed column similar to that used in water purification equipment or water softening equipment that uses ion exchange resins, which have been carried out industrially in the past.
Water is passed through this, and as shown in equation (1) below,
After ion exchange adsorption of NH 4 -N, aqueous solutions of alkali metal or alkaline earth metal hydroxides, carbonates, chlorides, etc. A regeneration method has been used to recover the NH 4 -N ion exchange adsorption ability of the cation exchanger by desorbing the NH 4 -N ion exchange. R・Na+NH 4 + →R・NH 4 +Na + (1) R・NH 4 +Na + →R・Na+NH 4 + (2) However, in this regeneration method, the selectivity of the cation exchanger for adsorption is Since NH 4 + ≧Na + , a large amount of Na + is required to regenerate a cation exchanger in which NH 4 + is ion-exchanged and adsorbed, and regeneration takes a long time. Furthermore, discharge of regeneration waste liquid containing desorbed NH 4 + is unavoidable. Furthermore, since some desorbed NH 4 + remains in the cation exchanger packed bed after regeneration, it is necessary to wash the inside of the packed bed with water. The present invention was made in view of the current situation, and its purpose is to effectively bring Na + , etc. into contact with a cation exchanger that has ion-exchanged and adsorbed NH 4 -N, and at the same time desorb it. An object of the present invention is to provide a method for removing NH4 -N from wastewater, which efficiently regenerates a cation exchanger by gasifying NH4 -N. In order to achieve the above object, the present invention has the following configuration. That is, the method for removing ammonia nitrogen from wastewater of the present invention involves supplying a sodium ion (Na + )-containing regenerating solution with a pH of 10 or more to a cation exchanger layer that has ion-exchanged and adsorbed ammonia nitrogen, and at the same time passing gas through the cation exchanger layer. This method is characterized by regenerating the ion exchanger layer. The present inventors have discovered that when a cation exchanger that has ion-exchanged and adsorbed NH4 -N is regenerated with a regenerating solution containing Na + , if NH4 -N desorbed from the cation exchanger is present in the regenerating solution, We have confirmed through experiments that this has an adverse effect on the regeneration of the cation exchanger, and have completed the present invention as a result of repeated studies on means to prevent this desorbed NH 4 -N from being present in the regeneration solution. be. According to the present invention, in order to prevent the NH 4 -N desorbed from the cation exchanger from existing in the regenerating liquid, a strongly alkaline Na + -containing regenerating liquid with a pH of 10 or higher is used as the regenerating liquid. In particular, within the system
NH 4 + is converted to NH 3 , and during regeneration, a gas such as air is introduced (blown) into the cation exchanger layer to diffuse the desorbed NH 4 −N, that is, NH 3 to the outside of the system ( (Hereinafter, this will be abbreviated as gasification)
It can be prevented from remaining in the regenerating liquid.
At this time, it is advantageous for the pH of the regenerated liquid to be 10 or higher; if it is lower than this, the gasification rate will drop significantly. This means that NH 3 and
The abundance ratio of NH 4 + can be confirmed by examining the dissociation constant as follows. NH 3 and NH 4 + in an aqueous solution exist in the state shown by the following formula. NH 3 +H 2 ONH 4 + +OH - (3) The percentage of NH 3 present in this case can be calculated as follows. K=[ NH4 + ][OH - ]/[ NH3 ][
H 2 O] In a dilute solution, [H 2 O] = constant, so Kb = [NH + ] [OH] / [NH 3 ] and Kw = [H + ] [OH - ]. OH - ]=Kw/[H + ] Here, Kb at 250℃ is 1.8×10 -5 mol/
, Kw is 10 -14 (mol/) 2 , and the percentage of NH 3 at each PH can be calculated. For example, 25℃,
In PH10, Thus, the NH 3 percentage at pH 7 to 11 is as shown in the table below.
【表】
表より明らかなように、PH10以下では、NH3の
存在百分率は著しく低下する。したがつて本発明
における再生液のPHは10以上とすることが必要で
あり、かくすることによりガスの導通吹込みによ
りNH4−Nをガス化除去し、再生液中に残留しな
いようにすることができる。なお、再生時の再生
液のPHは、それが高い程、液中でのNH3としての
存在比が高いため望ましいが、実用上、液中の
NH4 +が約90%以上NH3として存在するPH10付近
以上であれば十分である。
再生剤としてのNa+量は、従来法においては吸
着しているNH4 +量の10倍以上必要であるが、本
発明によればNH4 +量の2倍以上であれば十分で
ある(後記実施例の説明参照)。これは、再生液
中に浸漬した陽イオン交換体層内へのガス(空
気)の吹込みが陽イオン交換体層と再生液の接触
を促進し、陽イオン交換体層にイオン交換吸着し
ているNH4 +と再生液中のNa+とのイオン交換反
応を順調に進行させるためと考えられる。
Na+含有物質としては、NaOH、Na2CO3、
NaCl等あるいはそれらの混合物を挙げることが
できるが、PH調整及び使用量の点からNaOHが特
に適当である。すなわち、NaOH溶液を用いた場
合、Na+とイオン交換脱離したNH4 +は、再生液
がアルカリ性であるため、下記(4)式に示されるよ
うにNH3として多く存在し、続いてカラム内に吹
き込んだガス(空気)により直ちに再生液中より
NH3ガスとして排除されるためであり、このよう
に再生液中に脱離したNH4 +が残留しないので陽
イオン交換体にイオン交換吸着しているNH4 +の
脱離速度が低下せず、少量のNa+で良好に再生さ
れるのである。
NH4 +NH3+H+ (4)
再生液にNaCl溶液を用いた場合には、再生液
が中性であるため解離したNH4 +の大部分はその
ままNH4 +として存在しているため、ガス(空
気)を吹込んでも再生液中よりガス化排除され難
く再生液中に残留するので良好な結果は得られな
いが、再生液としてNaCl、PH上昇剤としてNaOH
等を混合して使用すれば有効である。
本発明は、常温で十分効果を発揮することがで
きるが、再生時の温度を例えば80〜90℃程度まで
高めることにより更に良好な結果を得ることがで
きる。又、本発明においては、再生液中にNH4 +
が残留しないため、再生廃液はカラムより抜き取
りそのまま循環再使用が可能であり、又、再生後
の陽イオン交換体カラムも水洗することなくその
まま排水の処理を行なつても初期にNH4 +がリー
クすることはない。
本発明における陽イオン交換体としては、天然
及び合成ゼオライト等あるいは通常用いられる陽
イオン交換樹脂を任意選択して使用することがで
き、後者としてはポリスチレン系スルホン酸型樹
脂のような強酸性陽イオン交換樹脂が適当であ
る。ゼオライトの吸着に対する選択性はNH4 +>
Na+>Ca++であるが、陽イオン交換樹脂のイオン
交換選択性は一般的には原子価の大きい程大であ
り、(>Ca++>NH4 +>Na+……)、強酸性陽イオ
ン交換樹脂ではCa++≫NH4 +Na+である。この
ため陽イオン交換樹脂の場合にもNa+で樹脂の再
生は可能である。しかしCa++はNH4 +より選択性
が大であるため、再生はできても次の吸着工程で
NH4 +の吸着能が著しく低下する(Ca型になつて
いるため)。
本発明の方法の実施は次のようにして行なう。
Na型陽イオン交換体層にNH4 +を含む排水を通し
処理水を得る。NH4 +をイオン交換吸着した陽イ
オン交換体層に再生液を注入した後、陽イオン交
換体層にガスを導通し該ガスを排出させる。陽イ
オン交換体の再生終了後、再生廃液を抜き取り再
び排水の処理に供する。以上の操作を複数の陽イ
オン交換体層について行ない排水の連続処理を行
なうことができる。
次に本発明を実施例により説明するが、本発明
はこれらによりなんら限定されるものではない。
参考例 1
天然ゼオライト0.1を充填したカラムに
NH4 +30ppmを含む排水を流速1/時で通水し
たところ、流出水中にNH4 +が1ppmリークするま
での処理排水量はゼオライト容量の180倍であつ
た。
実施例 1
参考例1のNH4 +をイオン交換吸着したゼオラ
イトカラムに、再生剤として3%NaOH溶液(PH
≒14)0.3を添加し、ゼオライト層をNaOH溶
液に浸漬後、カラム内に空気を5/分で1時間
吹き込んだ後、NaOH溶液をカラムより抜き取
り、再び参考例1の方法により排水の処理を行な
つたところ、流出水中にNH4 +が1ppmリークする
までの処理排水量はゼオライト容量の180倍であ
つた。
実施例 2
再生剤を1%NaOH溶液(PH≒13.5)0.3とし
た以外は実施例1と同様にしてゼオライトの再生
を行ない、続いて排水の処理を行なつたところ、
流出水中にNH4 +が1ppmリークするまでの処理排
水量はゼオライト容量の170倍であつた。
実施例 3
再生剤を0.5%NaOH溶液(PH≒13)0.3とし
た以外は実施例1と同様にしてゼオライトの再生
を行ない、続いて排水の処理を行なつたところ、
流出水中にNH4 +が1ppmリークするまでの処理排
水量はゼオライト容量の100倍であつた。
比較例 1
参考例1のNH4 +をイオン交換吸着したゼオラ
イトカラムに、再生剤として2.5%NaCl溶液(PH
≒7)3を1/時で通液してゼオライトを再
生し、更に、水1を流速1/時で通水してカ
ラムの水洗を行なつた後、参考例1の方法により
排水の処理を行なつたところ、流出水中にNH4 +
が1ppmリークするまでの処理排水量はゼオライ
ト容量の170倍であつた。
比較例 2
参考例1のNH4 +をイオン交換吸着したゼオラ
イトカラムに1.0%NaOH溶液3を流速1/
時で通液してゼオライトを再生し、更に、水3
を流速1/時で通水してカラムの水洗を行なつ
た後、再び参考例1の方法により排水の処理を行
なつたところ、流出水中にNH4 +が1ppmリークす
るまでの処理排水量はゼオライト容量の180倍で
あつた。
比較例 3
参考例1のNH4 +をイオン交換吸着したゼオラ
イトに10%NaOH溶液(PH≒14)0.3を添加
し、ゼオライトをNaOH溶液に2時間浸漬後、
NaOH溶液をカラムより抜き取り、水3を流速
1/時で通水してカラムの水洗を行なつた後、
再び参考例1の方法により排水の処理を行なつた
ところ、流出水中にNH4 +が1ppmリークするまで
の処理排水量はゼオライト容量の120倍であつ
た。
比較例 4
再生剤を15%NaCl溶液(PH≒7)0.3とした
以外は実施例1と同様にしてゼオライトの再生を
行ない、続いて排水の処理を行なつたところ、流
出水中にNH4 +が1ppmリークするまでの処理排水
量はゼオライト容量の90倍であつた。
以上の実施例及び比較例で得られた結果及び併
せて行なつた再生液中の脱離NH4 +の蓄積による
イオン交換吸着能の状態等の観察の結果から、次
のことがわかる。
実施例1及び参考例1、2の結果から、NH4 +
を30ppm含む排水処理については、流出水中に
NH4 +が1ppmリークするまでにゼオライト容量の
180倍程度の処理が可能であり、このNH4 +をイオ
ン交換吸着したゼオライトは、NaCl又はNaOH溶
液で十分な再生が可能である。しかし、再生剤と
してのNa+量は、前記(2)式に示したように、理論
的には吸着しているNH4 +と当量で良いはずであ
るが、NH4 +の方がNa+よりイオン交換吸着に対
する選択性が大であるため、比較例1及び2にお
いては、Na+/NH4 +は29及び25といずれの場合
もNa+の量は吸着しているNH4 +の10倍以上必要
であり、これ以下では十分な再生結果は得られな
かつた。これに対し、実施例1〜3においては、
再生剤としてのNa+の量は比較例1、2の場合に
比べはるかに少なくてよく、吸着しているNH4 +
量の2倍以上であれば十分である。(Na+/NH4 +
は、実施例1では7.5、実施例2では2.5、実施例
3では1.25である)又、比較例においては、再生
後のゼオライトカラムは水洗を十分に行なわない
と、再生時にゼオライトから脱離したNH4 +がカ
ラム内に残留しており、次の排水処理の初期にこ
のNH4 +が流出して好ましくなかつた。又、再生
廃液中にはゼオライトより脱離した高濃度の
NH4 +(比較例1、2では200〜300ppm)を含ん
でおり、この再生廃液は更に処理が必要であつ
た。これに対し、実施例においては、水洗は必要
なく、再生液中に残留するNH4 +も僅かであつ
た。
比較例3は、再生剤であるNa+を含む溶液中に
NH4 +をイオン交換吸着したゼオライトを浸漬し
て再生を行なう方法であるが、これによれば、比
較例1、2のように再生液を通水する方法より少
ない再生液量で再生を行なうことができる。しか
し、このような浸漬再生法では、再生液中にゼオ
ライトから脱離したNH4 +が蓄積するため、ゼオ
ライトからのNH4 +の脱離速度が低下し十分な再
生結果は得られなかつた。更に又、比較例4の結
果から明らかなように、再生剤としてNaClのみ
を使用した場合には、空気を吹き込んでも良好な
再生は得られなかつた。
参考例 2
強酸性陽イオン交換樹脂(ポリスチレン系スル
ホン酸型樹脂)0.1を充填したカラムに、
NH4 +30ppmを含む排水を流速1/時で通水し
たところ、流出水中にNH4 +が1ppmリークするま
での処理水量は陽イオン交換樹脂容量の190倍で
あつた。
実施例 4
参考例2のNH4 +をイオン交換吸着した陽イオ
ン交換樹脂カラムに、再生剤として0.005%
NaOH及びNaCl混合溶液(PH≒11)0.3を添加
し陽イオン交換樹脂を該混合溶液に浸漬後、カラ
ム内に空気を5/分で1時間吹き込んだ後、該
混合溶液をカラムより抜き取り、再び参考例2の
方法により排水の処理を行なつたところ、流出水
中にNH4 +が1ppmリークするまでの処理排水量は
陽イオン交換樹脂容量の180倍であり、Na+量は
NH4 +量の2.4倍であつた。
この結果から、本発明は陽イオン交換体が陽イ
オン交換樹脂である場合にも適用され、再生に効
果を発揮できることがわかる。
以上詳細に説明したように、本発明によれば、
陽イオン交換体と再生剤の接触が促進され、更に
再生液中には脱離NH4 +が残留しないので、少量
の再生剤によりNH4 +をイオン交換吸着した陽イ
オン交換体の良好な再生を行なうことができる。[Table] As is clear from the table, when the pH is below 10, the percentage of NH 3 present decreases significantly. Therefore, it is necessary that the pH of the regenerating liquid in the present invention is 10 or more, and by doing so, NH 4 -N is gasified and removed by the gas conduction blowing, so that it does not remain in the regenerating liquid. be able to. Note that the higher the PH of the regenerated liquid during regeneration, the higher the abundance ratio of NH 3 in the liquid, which is desirable.
It is sufficient that the pH is around 10 or higher, at which about 90% or more of NH 4 + exists as NH 3 . In the conventional method, the amount of Na + as a regenerant is required to be at least 10 times the amount of NH 4 + adsorbed, but according to the present invention, it is sufficient if it is at least twice the amount of NH 4 + ( (See description of Examples below). This is because the blowing of gas (air) into the cation exchanger layer immersed in the regeneration liquid promotes contact between the cation exchanger layer and the regeneration liquid, and ion exchange adsorption occurs in the cation exchanger layer. This is thought to be due to the smooth progress of the ion exchange reaction between the NH 4 + in the regenerating solution and the Na + in the regenerating solution. Na + containing substances include NaOH, Na 2 CO 3 ,
Examples include NaCl and mixtures thereof, but NaOH is particularly suitable from the viewpoint of pH adjustment and usage amount. In other words, when a NaOH solution is used, NH 4 + desorbed by ion exchange with Na + exists in large quantities as NH 3 as shown in equation (4) below because the regenerating solution is alkaline, and is then transferred to the column. The gas (air) blown into the tank immediately removes the regenerated liquid from the inside.
This is because the desorbed NH 4 + does not remain in the regeneration liquid, so the desorption rate of NH 4 + adsorbed on the cation exchanger does not decrease. , can be regenerated well with a small amount of Na + . NH 4 + NH 3 +H + (4) When a NaCl solution is used as the regeneration solution, most of the dissociated NH 4 + remains as NH 4 + because the regeneration solution is neutral. Even if gas (air) is blown into the regenerated liquid, it is difficult to gasify and be removed from the regenerated liquid and remains in the regenerated liquid, so good results cannot be obtained.
It is effective if used in combination. Although the present invention is sufficiently effective at room temperature, even better results can be obtained by raising the temperature during regeneration to, for example, about 80 to 90°C. In addition, in the present invention, NH 4 +
Since no residue remains, the regenerated waste liquid can be extracted from the column and recycled as it is for reuse.Also, even if the cation exchanger column after regeneration is treated as wastewater without being washed with water, NH 4 + No leaks. As the cation exchanger in the present invention, natural and synthetic zeolites or commonly used cation exchange resins can be optionally used, and the latter include strong acid cations such as polystyrene-based sulfonic acid type resins. Replacement resin is suitable. The selectivity of zeolite for adsorption is NH 4 + >
Na + >Ca ++ , but the ion exchange selectivity of cation exchange resins generally increases as the valence increases; (>Ca ++ >NH 4 + >Na + ...), strong acids In the case of cation exchange resins, Ca ++ ≫NH 4 + Na + . Therefore, even in the case of cation exchange resins, it is possible to regenerate the resin with Na + . However, Ca ++ is more selective than NH 4 + , so even if it can be regenerated, it will be lost in the next adsorption step.
The adsorption capacity for NH 4 + is significantly reduced (because it is in the Ca type). The method of the invention is carried out as follows.
Wastewater containing NH 4 + is passed through the Na-type cation exchanger layer to obtain treated water. After a regenerating liquid is injected into the cation exchanger layer that has ion-exchanged and adsorbed NH 4 + , gas is introduced into the cation exchanger layer and the gas is discharged. After the cation exchanger is regenerated, the regenerated waste liquid is extracted and used for wastewater treatment again. The above operations can be performed for a plurality of cation exchanger layers to continuously treat wastewater. EXAMPLES Next, the present invention will be explained with reference to Examples, but the present invention is not limited to these in any way. Reference example 1 In a column packed with natural zeolite 0.1
When wastewater containing 30 ppm of NH 4 + was passed through at a flow rate of 1/hour, the amount of waste water treated until 1 ppm of NH 4 + leaked into the effluent was 180 times the zeolite capacity. Example 1 A 3% NaOH solution (PH
≒14) 0.3 was added, the zeolite layer was immersed in the NaOH solution, air was blown into the column at 5/min for 1 hour, the NaOH solution was extracted from the column, and the wastewater was treated again by the method of Reference Example 1. As a result, the amount of wastewater treated until 1 ppm of NH 4 + leaked into the effluent was 180 times the zeolite capacity. Example 2 Zeolite was regenerated in the same manner as in Example 1 except that the regenerant was a 1% NaOH solution (PH≒13.5) of 0.3, and then the wastewater was treated.
The amount of treated wastewater until 1 ppm of NH 4 + leaked into the effluent was 170 times the zeolite capacity. Example 3 Zeolite was regenerated in the same manner as in Example 1 except that the regenerant was a 0.5% NaOH solution (PH≒13) of 0.3, and then the wastewater was treated.
The amount of treated wastewater until 1 ppm of NH 4 + leaked into the effluent was 100 times the zeolite capacity. Comparative Example 1 A 2.5% NaCl solution (PH
≒ 7) After regenerating the zeolite by passing 3 at a flow rate of 1/hour, and washing the column by passing water 1 at a flow rate of 1/hour, the wastewater was treated by the method of Reference Example 1. When this process was carried out, NH 4 + was found in the effluent water.
The amount of wastewater treated until 1 ppm leaked was 170 times the zeolite capacity. Comparative Example 2 1.0% NaOH solution 3 was applied to the zeolite column in which NH 4 + of Reference Example 1 was adsorbed by ion exchange at a flow rate of 1/2.
The zeolite is regenerated by passing the liquid through it at a time, and then the water
After washing the column with water at a flow rate of 1/hour, the wastewater was treated again using the method of Reference Example 1. The amount of wastewater treated until 1ppm of NH 4 + leaked into the effluent was: It was 180 times the zeolite capacity. Comparative Example 3 0.3 of a 10% NaOH solution (PH≒14) was added to the zeolite of Reference Example 1 on which NH 4 + was adsorbed by ion exchange, and after immersing the zeolite in the NaOH solution for 2 hours,
After extracting the NaOH solution from the column and washing the column with water at a flow rate of 1/hour,
When wastewater was treated again by the method of Reference Example 1, the amount of treated wastewater until 1 ppm of NH 4 + leaked into the effluent was 120 times the zeolite capacity. Comparative Example 4 Zeolite was regenerated in the same manner as in Example 1 except that the regenerant was a 15% NaCl solution (PH≒7) of 0.3, and then the wastewater was treated. As a result, NH 4 + The amount of wastewater treated until 1 ppm leaked was 90 times the zeolite capacity. From the results obtained in the above Examples and Comparative Examples and the results of observations of the state of ion exchange adsorption capacity due to the accumulation of desorbed NH 4 + in the regenerant, the following can be found. From the results of Example 1 and Reference Examples 1 and 2, NH 4 +
For wastewater treatment containing 30ppm of
of zeolite capacity until 1ppm of NH4 + leaks.
It is possible to process approximately 180 times more, and this zeolite with ion exchange adsorption of NH 4 + can be sufficiently regenerated with NaCl or NaOH solution. However, as shown in equation (2) above, the amount of Na + as a regenerant should theoretically be equivalent to the amount of adsorbed NH 4 + ; In Comparative Examples 1 and 2, Na + /NH 4 + was 29 and 25, and in both cases the amount of Na + was 10% of the adsorbed NH 4 + . More than twice as much is required, and if it is less than this, sufficient reproduction results cannot be obtained. On the other hand, in Examples 1 to 3,
The amount of Na + as a regenerant may be much smaller than in Comparative Examples 1 and 2, and the amount of Na + that has been adsorbed
It is sufficient that the amount is at least twice the amount. (Na + /NH 4 +
is 7.5 in Example 1, 2.5 in Example 2, and 1.25 in Example 3) In addition, in the comparative example, if the zeolite column after regeneration was not sufficiently washed with water, the zeolite was desorbed from the zeolite during regeneration. NH 4 + remained in the column, and this NH 4 + leaked out at the beginning of the next wastewater treatment, which was undesirable. In addition, the recycled waste liquid contains high concentrations of desorbed from zeolite.
Containing NH 4 + (200 to 300 ppm in Comparative Examples 1 and 2), this recycled waste liquid required further treatment. On the other hand, in the examples, water washing was not necessary and only a small amount of NH 4 + remained in the regenerated solution. Comparative Example 3 is a solution containing Na + as a regenerant.
This method performs regeneration by immersing zeolite that has ion-exchanged and adsorbed NH 4 + , but according to this method, regeneration can be performed using a smaller amount of regenerating liquid than the method of passing regenerating liquid through water as in Comparative Examples 1 and 2. be able to. However, in such an immersion regeneration method, NH 4 + desorbed from the zeolite accumulates in the regeneration solution, so the rate of desorption of NH 4 + from the zeolite decreases, and sufficient regeneration results cannot be obtained. Furthermore, as is clear from the results of Comparative Example 4, when only NaCl was used as the regenerant, good regeneration could not be obtained even when air was blown. Reference example 2 A column packed with 0.1 of a strong acid cation exchange resin (polystyrene-based sulfonic acid type resin) was
When wastewater containing 30 ppm of NH 4 + was passed through at a flow rate of 1/hour, the amount of water treated until 1 ppm of NH 4 + leaked into the effluent was 190 times the capacity of the cation exchange resin. Example 4 0.005% as a regenerant was added to the cation exchange resin column in which NH 4 + was ion exchange adsorbed in Reference Example 2.
After adding 0.3 of a NaOH and NaCl mixed solution (PH≒11) and immersing the cation exchange resin in the mixed solution, air was blown into the column at a rate of 5/min for 1 hour, and the mixed solution was extracted from the column and again. When wastewater was treated using the method of Reference Example 2, the amount of treated wastewater until 1ppm of NH 4 + leaked into the effluent was 180 times the capacity of the cation exchange resin, and the amount of Na + was
It was 2.4 times the amount of NH 4 + . This result shows that the present invention can be applied even when the cation exchanger is a cation exchange resin, and can be effective in regeneration. As explained in detail above, according to the present invention,
Since the contact between the cation exchanger and the regenerant is promoted, and no desorbed NH 4 + remains in the regenerant, a small amount of the regenerant can effectively regenerate the cation exchanger that has ion-exchanged and adsorbed NH 4 + . can be done.
Claims (1)
アンモニア性窒素を除去する方法において、アン
モニア性窒素をイオン交換吸着した陽イオン交換
体層にPH10以上のナトリウムイオン含有再生液を
供給すると共にガスを導通してイオン交換体層を
再生することを特徴とする排水中のアンモニア性
窒素除去法。 2 陽イオン交換体がゼオライト又は陽イオン交
換樹脂である特許請求の範囲第1項記載の排水中
のアンモニア性窒素除去法。 3 ナトリウムイオン含有再生液が水酸化ナトリ
ウム、炭酸ナトリウム又はこれらを塩化ナトリウ
ムと混合した水溶液である特許請求の範囲第1項
記載の排水中のアンモニア性窒素除去法。 4 ガスが空気である特許請求の範囲第1項記載
の排水中のアンモニア性窒素除去法。[Scope of Claims] 1. In a method for removing ammonia nitrogen from waste water by bringing the waste water into contact with a cation exchange layer, the cation exchange layer that has ion-exchanged and adsorbed ammonia nitrogen contains regenerated sodium ions with a pH of 10 or more. A method for removing ammonia nitrogen from wastewater, characterized by supplying a liquid and supplying a gas to regenerate an ion exchanger layer. 2. The method for removing ammonia nitrogen from wastewater according to claim 1, wherein the cation exchanger is a zeolite or a cation exchange resin. 3. The method for removing ammonia nitrogen from wastewater according to claim 1, wherein the sodium ion-containing regenerating liquid is sodium hydroxide, sodium carbonate, or an aqueous solution of these mixed with sodium chloride. 4. The method for removing ammonia nitrogen from wastewater according to claim 1, wherein the gas is air.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1147678A JPS54104649A (en) | 1978-02-06 | 1978-02-06 | Removal of ammoniac nitrogen in waste water |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1147678A JPS54104649A (en) | 1978-02-06 | 1978-02-06 | Removal of ammoniac nitrogen in waste water |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS54104649A JPS54104649A (en) | 1979-08-17 |
JPS622875B2 true JPS622875B2 (en) | 1987-01-22 |
Family
ID=11779111
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP1147678A Granted JPS54104649A (en) | 1978-02-06 | 1978-02-06 | Removal of ammoniac nitrogen in waste water |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS54104649A (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4695387A (en) * | 1985-05-07 | 1987-09-22 | Advanced Separation Technologies Incorporated | Removal of ammonia from wastewater |
KR100347676B1 (en) * | 2000-04-29 | 2002-08-07 | 배병욱 | Method for Treating Waste Water for Reuse in Nitrate Exchange System |
CN113387413A (en) * | 2021-05-19 | 2021-09-14 | 中核四0四有限公司 | Ion exchange method for uranium-containing wastewater treatment in nitric acid and carbonic acid mixed system |
CN115608319A (en) * | 2022-12-08 | 2023-01-17 | 江西理工大学 | Modified vermiculite adsorbent for removing ammonia nitrogen in water and preparation and regeneration method thereof |
-
1978
- 1978-02-06 JP JP1147678A patent/JPS54104649A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS54104649A (en) | 1979-08-17 |
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